Aircraft carrier and other type ships with aviation capability having flight and elevator decks are provided with numerous spaced-apart tie down fittings to which hooks on chains connected with aircraft may be removably attached. The tie-down fitting are located every several feet in a regular pattern about the deck where aircraft are to be stored.
Aircraft are normally provided with high strength structural means adjacent the nose wheel and main landing gear for receiving tie-down chains. When a hook at the other end of the chain is fastened into tie-down fittings located generally in opposite direction from both forward and aft locations on the aircraft, the aircraft is secured from movement across a deck resulting from ship dynamic forces and wind loads.
Problems arise when an aircraft on deck is not ideally positioned over the tie-down fittings, and there is no opportunity for obtaining oppositely extending anchoring tie-downs from both fore and aft positions on the aircraft. This situation is further complicated with larger aircraft where it is necessary to let a portion of the aircraft extend over the edge of the storage or elevator deck. There is illustrated in FIG. 1 a situation where aircraft 10 (helicopter) extends over the elevator edge, but is not ideally located with respect to tie down fittings 12, and, therefore, a good athwartship restraint cannot be obtained. While it is possible to reposition the aircraft at an angle on the elevator or storage deck, as illustrated in FIG. 2, for better tie down, it is an awkward location and a time consuming procedure to maneuver the aircraft with tractor and tow bar. An additional aircraft may also be loaded along side an aircraft when positioned as illustrated in FIG. 1.
General specifications for ships of the U.S. Navy require that carriers be provided with additional tie-down capability for aircraft parked with portions of their bodies projecting over the flight and elevator deck edges. The tie-down capabilities are cleats, staples, jack stays and other fitting. The ideal would be for the deck to extend farther outwardly, but this is not possible. Therefore, numerous designs have been proposed to meet the problem. One previous tie-down arrangement for an aircraft 110 is illustrated in FIG. 3. The aircraft is illustrated in parked position on the deck or hanger with its wheels 122 near fixed wheel stop 124 and its tail section 126 hanging over the edge. A tie down chain 128 is attached at one end to the hub of wheel 122 and at the other end to a bulwark 130 forming part of walkway 132 which runs along the edge of the deck. Another tie down chain cable 134 is secured between the bulwark 130 and attachment 136 on the aircraft. Tie down chain 128 restrains the aircraft from movement away from wheel stop 124. The stop prevents the aircraft wheel from running over the edge of the deck. The portion of tie down chain 128 in contact with wheel stop 124 is subject to chafing. Also, tie-down chain 128 is an obstruction to passage along walkway 132.
It is desired that there be provided a wheel stop adjacent the edge of the storage deck or elevator which is capable of defining not only an abutment but a tie-down anchor as well. It is to this objective that the present invention is directed.